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1 | dnl Copyright (C) 2000-2021 Free Software Foundation, Inc. |
2 | dnl | |
3 | dnl GCC is free software; you can redistribute it and/or modify | |
4 | dnl it under the terms of the GNU General Public License as published by | |
5 | dnl the Free Software Foundation; either version 3, or (at your option) | |
6 | dnl any later version. | |
7 | dnl | |
8 | dnl GCC is distributed in the hope that it will be useful, | |
9 | dnl but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | dnl GNU General Public License for more details. | |
12 | dnl | |
13 | dnl You should have received a copy of the GNU General Public License | |
14 | dnl along with GCC; see the file COPYING3. If not see | |
15 | dnl <http://www.gnu.org/licenses/>. | |
16 | ||
17 | dnl See whether strncmp reads past the end of its string parameters. | |
18 | dnl On some versions of SunOS4 at least, strncmp reads a word at a time | |
19 | dnl but erroneously reads past the end of strings. This can cause | |
20 | dnl a SEGV in some cases. | |
21 | AC_DEFUN([libiberty_AC_FUNC_STRNCMP], | |
22 | [AC_REQUIRE([AC_FUNC_MMAP]) | |
23 | AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works, | |
24 | [AC_TRY_RUN([ | |
25 | /* Test by Jim Wilson and Kaveh Ghazi. | |
26 | Check whether strncmp reads past the end of its string parameters. */ | |
27 | #include <sys/types.h> | |
28 | ||
29 | #ifdef HAVE_FCNTL_H | |
30 | #include <fcntl.h> | |
31 | #endif | |
32 | ||
33 | #ifdef HAVE_SYS_MMAN_H | |
34 | #include <sys/mman.h> | |
35 | #endif | |
36 | ||
37 | #ifndef MAP_ANON | |
38 | #ifdef MAP_ANONYMOUS | |
39 | #define MAP_ANON MAP_ANONYMOUS | |
40 | #else | |
41 | #define MAP_ANON MAP_FILE | |
42 | #endif | |
43 | #endif | |
44 | ||
45 | #ifndef MAP_FILE | |
46 | #define MAP_FILE 0 | |
47 | #endif | |
48 | #ifndef O_RDONLY | |
49 | #define O_RDONLY 0 | |
50 | #endif | |
51 | ||
52 | #define MAP_LEN 0x10000 | |
53 | ||
54 | main () | |
55 | { | |
56 | #if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE) | |
57 | char *p; | |
58 | int dev_zero; | |
59 | ||
60 | dev_zero = open ("/dev/zero", O_RDONLY); | |
61 | if (dev_zero < 0) | |
62 | exit (1); | |
63 | ||
64 | p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE, | |
65 | MAP_ANON|MAP_PRIVATE, dev_zero, 0); | |
66 | if (p == (char *)-1) | |
67 | p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE, | |
68 | MAP_ANON|MAP_PRIVATE, -1, 0); | |
69 | if (p == (char *)-1) | |
70 | exit (2); | |
71 | else | |
72 | { | |
73 | char *string = "__si_type_info"; | |
74 | char *q = (char *) p + MAP_LEN - strlen (string) - 2; | |
75 | char *r = (char *) p + 0xe; | |
76 | ||
77 | strcpy (q, string); | |
78 | strcpy (r, string); | |
79 | strncmp (r, q, 14); | |
80 | } | |
81 | #endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */ | |
82 | exit (0); | |
83 | } | |
84 | ], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no, | |
85 | ac_cv_func_strncmp_works=yes) | |
86 | rm -f core core.* *.core]) | |
87 | if test $ac_cv_func_strncmp_works = no ; then | |
88 | AC_LIBOBJ([strncmp]) | |
89 | fi | |
90 | ]) | |
91 | ||
92 | dnl See if errno must be declared even when <errno.h> is included. | |
93 | AC_DEFUN([libiberty_AC_DECLARE_ERRNO], | |
94 | [AC_CACHE_CHECK(whether errno must be declared, libiberty_cv_declare_errno, | |
95 | [AC_TRY_COMPILE( | |
96 | [#include <errno.h>], | |
97 | [int x = errno;], | |
98 | libiberty_cv_declare_errno=no, | |
99 | libiberty_cv_declare_errno=yes)]) | |
100 | if test $libiberty_cv_declare_errno = yes | |
101 | then AC_DEFINE(NEED_DECLARATION_ERRNO, 1, | |
102 | [Define if errno must be declared even when <errno.h> is included.]) | |
103 | fi | |
104 | ]) | |
105 | ||
106 | dnl See whether we need a declaration for a function. | |
107 | AC_DEFUN([libiberty_NEED_DECLARATION], | |
108 | [AC_MSG_CHECKING([whether $1 must be declared]) | |
109 | AC_CACHE_VAL(libiberty_cv_decl_needed_$1, | |
110 | [AC_TRY_COMPILE([ | |
111 | #include "confdefs.h" | |
112 | #include <stdio.h> | |
113 | #ifdef HAVE_STRING_H | |
114 | #include <string.h> | |
115 | #else | |
116 | #ifdef HAVE_STRINGS_H | |
117 | #include <strings.h> | |
118 | #endif | |
119 | #endif | |
120 | #ifdef HAVE_STDLIB_H | |
121 | #include <stdlib.h> | |
122 | #endif | |
123 | #ifdef HAVE_UNISTD_H | |
124 | #include <unistd.h> | |
125 | #endif], | |
126 | [char *(*pfn) = (char *(*)) $1], | |
127 | libiberty_cv_decl_needed_$1=no, libiberty_cv_decl_needed_$1=yes)]) | |
128 | AC_MSG_RESULT($libiberty_cv_decl_needed_$1) | |
129 | if test $libiberty_cv_decl_needed_$1 = yes; then | |
130 | AC_DEFINE([NEED_DECLARATION_]translit($1, [a-z], [A-Z]), 1, | |
131 | [Define if $1 is not declared in system header files.]) | |
132 | fi | |
133 | ])dnl | |
134 | ||
135 | # We always want a C version of alloca() compiled into libiberty, | |
136 | # because native-compiler support for the real alloca is so !@#$% | |
137 | # unreliable that GCC has decided to use it only when being compiled | |
138 | # by GCC. This is the part of AC_FUNC_ALLOCA that calculates the | |
139 | # information alloca.c needs. | |
140 | AC_DEFUN([libiberty_AC_FUNC_C_ALLOCA], | |
141 | [AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray, | |
142 | [AC_EGREP_CPP(webecray, | |
143 | [#if defined(CRAY) && ! defined(CRAY2) | |
144 | webecray | |
145 | #else | |
146 | wenotbecray | |
147 | #endif | |
148 | ], ac_cv_os_cray=yes, ac_cv_os_cray=no)]) | |
149 | if test $ac_cv_os_cray = yes; then | |
150 | for ac_func in _getb67 GETB67 getb67; do | |
151 | AC_CHECK_FUNC($ac_func, | |
152 | [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func, | |
153 | [Define to one of _getb67, GETB67, getb67 for Cray-2 and Cray-YMP | |
154 | systems. This function is required for alloca.c support on those | |
155 | systems.]) break]) | |
156 | done | |
157 | fi | |
158 | ||
159 | AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction, | |
160 | [AC_TRY_RUN([find_stack_direction () | |
161 | { | |
162 | static char *addr = 0; | |
163 | auto char dummy; | |
164 | if (addr == 0) | |
165 | { | |
166 | addr = &dummy; | |
167 | return find_stack_direction (); | |
168 | } | |
169 | else | |
170 | return (&dummy > addr) ? 1 : -1; | |
171 | } | |
172 | main () | |
173 | { | |
174 | exit (find_stack_direction() < 0); | |
175 | }], | |
176 | ac_cv_c_stack_direction=1, | |
177 | ac_cv_c_stack_direction=-1, | |
178 | ac_cv_c_stack_direction=0)]) | |
179 | AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction, | |
180 | [Define if you know the direction of stack growth for your system; | |
181 | otherwise it will be automatically deduced at run-time. | |
182 | STACK_DIRECTION > 0 => grows toward higher addresses | |
183 | STACK_DIRECTION < 0 => grows toward lower addresses | |
184 | STACK_DIRECTION = 0 => direction of growth unknown]) | |
185 | ]) |